Electric thread cutter



J1me 1964 e. M. MARKS ELECTRIC THREAD CUTTER Filed Jan. 2, 1962 FIG. 5

INVENTOR. GEORGE M. MARKS FIG.6

United, States Patent 31,135,298 7 ELECTRIC THREAD CUTT"R George M.Marks, Rte. 6, Greenville, S.C. Filed Jan. 2, 1962, Ser. No. 163,463 4Claims' (Cl. 139-463) justment and sharpening, but are not reliable forsevering synthetic thread composed of twisted fibers such as nylon,Celanese, Dacron, Orlon and like tough thermoplastic materials. Not onlyare such threads difficult to shear cleanly, but when cut, the fibersuntwist and ravel because of plastic memory.

When cloth is woven in well known power looms, the starting and finishlengths of the weft thread of each bobbin carried by the shuttleprojects from the edge of the fabric and is held linear by clampingmeans. These threads cannot be cut close to the edge of the cloth byordinary shear methods since the raveling would run into the cloth, and,thus, render a portion thereof defective. This results in the necessityfor shearing the thread with a predetermined length projecting from thecloth which is laterremoved by hand methods.

The present invention to be hereinafter described is one embodiment ofthe invention adapted to power power loom 2 by screw 3 which alsoretains terminal 4 of a high tension conductor 5. The upper end of afiat spring 6 is also retained under block 1 in contact with the machineby screw 3. The lower free portion of spring 6 retains a dielectric body7, preferably made from porcelain or other high dielectric material, andisrretained in fixed relation thereon by screw 8, as shown.

'An integral V-shaped guide 9 is formed in one side of body 7 and isshaped for frictional engagement with the edge surface of the cloth inthe loom.

A lower'electrode 10 is secured tobody 7 by screw 11 in contact with theupturned lower end of spring 6, as shown. An'upper electrode 12 issecured to body 7 by screw 13 and is positioned, as shown, providing afixed elongated spark gap 14 with parallel knife-like edges. In theinterest of long life, the electrodes are best made of metal alloy highin nickel or tungsten or from metals in the platinum group.

A flexible conductor 15 has a terminal 16 on its lower end also retainedby screw 13. A second terminal 16 on conductor 15 wide terminal 17 areretained to block 1 by screw 18. A second high tension conductor 19terminates in terminal 17.

FIG. 2 is a fragmentary front view of the spark'gap assembly applied toa typical power loom with a fabric 2t? in the process of being wovenwith a pair of weft looms and overcomes the above objections anddisadvantages by the provision of an automatic means for severingthreads in close proximity with the edge of woven synthetic cloth andhaving an. additional advantage of welding together the severed fibrousends of the filaments of the thread into a revel-proof nodule and is aprincipal object of the invention.

A further object ofrthe invention is the'provision of a spark gap meansfor intercepting and severing threads by heat from a high voltage sparkdischarge.

Another object of the invention is the provision of a spark gapincluding an electric transformation means for generating a continuousspark in said gap including switch and circuit means responsive to themovement of a thread for severing same by the heat of said spark whenthe thread is moved into the gap.

A further object of the invention is the provision of a spark gapmovably positioned to intercept laterally moving weft threads projectingfrom the cloth in a power loom and severing same in close proximity tothe edge of said cloth by means of a high tension spark generated acrosssaid gap.

These and other objects and advantages of the invention are describedand shown in the following specification and drawing in which:

FIG. 1 is a perspective view of a thread severing spark gap assembly fora textile machine.

FIG. 2 is a front elevation of the spark gap assembly, shown FIG. 1,applied to a power loom. I

FIG.- 3 is a side elevation of the device, shown FIG. 2.

FIG. 4 is a greatly enlarged illustration of a section of multiplefilament thread.

FIG. 5 illustrates the thread, shown FIG. 4, after heat severance.

FIG.'6 is a schematic diagram of electric components and circuit forenergizing the spark gap, shown FIG. 1. Referring to FIGS. 1 and .2, adielectric block 1 is ecured to a fixed grounded conductive portion of athreads 21 representing the end and start portion of the thread in apair of bobbins. These threads are retained in a linear position by atypical weft thread clamp means illustrated by clamp elements 22-22 inthey loom 2.

A sensitive self-restoring normally open switch 23 is secured to themachine with the'act'uatorarm 24 thereof positioned to be engaged'andmoved by the forward movement of the threads 21, better shown inFIG; 3.

It is now apparent that when the cloth 20 as woven is moved in thedirection shown by arrow, FIG. 3, the actuator 24 will be encountered bythe threads 21, held and moved by the clamp 22, and operate the switchinto closed position just prior to the thread entry into the spark gap14 between electrodes 10 and 12.

FIG. 6 illustrates a circuit including atypical A.C. step-up ignitiontransformer 25 having the primary 26 thereof connected to a source ofconventional A.C. electric energy L -L with switch 23 in seriestherewith. The high potential secondary 27 of the transformer isconnected by conductors 19 and 5 to electrode terminals 18 and 3corresponding to elements 15 and 16 and electrodes 12 and 10respectively, as shown, with the conductor 5 grounded to the loom 2 as asafety measure.

In operation and under the assumption that the woven cloth in themachine is moving in the direction shown by arrow in FIG. 3, each pairof weft threads 21 will engage actuator 24 of switch 23 and move sameinto closed position and, thus, produce a continuous spark across thegap 14. Concurrently, the threads 21 will enter the gap 14 and beintersected by the spark therein resulting in the severance of thethread by melting and the welding together of the filaments in the endsof the thread. Simultaneous with theseverance of the thread,- theactuator arm 24 will permit the switch to return to its normal openposition and de-energize the spark gap.

FIG. 4 illustrates a portion of multi-filament thread 31 greatlyenlarged and FIG. 5 illustrates the welded bonded nodule ends 32following severance by the electric spark in the gap 14. g

It is to be noted that since the spark will always follow the shortestpath between the electrodes, the elongated electrodes are provided forlong life since the spark may travel the entire length of the electrodesas portions of the edges thereof deteriorate. Furthermore, the

narrow elongated gap provides for containing the spark 3 in a linearpath for severing weft threads close to the edge of the cloth.

It is also to be noted that alternate electric means may be used forgenerating the high potential required in the spark gap such as the useof radio frequency or direct current high potential generators.

It has been found that the above described device may also be used forsevering small metal filaments as well as combustible threads such ascotton, wool and silk by incorporating certain modifications inconstruction.

It is understood that certain modifications in the above describedconstruction, utilizing the features described, are intended to comewithin the scope of the appended claims.

Having described my invention, I claim:

1. In a textile machine, apparatus for severing threads projecting fromthe edge of a cloth comprising a pair ofelectrodes secured inpredetermined fixed spaced relation by dielectric means forming a sparkgap, a source of electric energy of predetermined potential connected tosaid electrodes adapted to produce a continuous spark across said gap, aholding means adapted to retain threads in a substantially linearposition for lateral entrance into said gap, said holding meansproviding relative motion between said spark gap and said threads forentering the latter into said gap spaced between said electrodes wherebythe heat of said spark severs said threads when said threads moverelative thereto, and guide means disposed substantially perpendicularto the plane of said cloth, said guide means carrying said electrodesand adapted to engage the edge of said cloth from which said threadsextend after'said threads are severed by the heat of said spark, saidguide means movable with uniform distance from said edge.

2. Apparatus in accordance with claim 1 wherein said threads aresynthetic threads. 3. Apparatus in accordance with claim '1 whereinthere respect to the edge of said cloth to maintain said gap at o isprovided an electric transformer interconnecting said electrodes andsaid sources of electric energy to produce a continuous spark acrosssaid gap when energized and electric switch means between said source ofelectric energy and said electrodes, said electric switch means beingactuated by the movement of said threads in engagement therewith.

4. In a power loom, a device of the character described for severingfilaments from the edge of moving material, a fixed spark gap comprisinga pair of electrodes secured to an insulating body, said electrodesterminating in a pair of oppositely positioned parallel spaced blades ofpredetermined length forming said gap, said body including a guide,yieldable means supporting said body adjacent the said edge of saidmaterial and disposed substantially perpendicular to the plane of saidmaterial with said guide in responsive slidable engagement with the saidedge of said material, electric means connected to said electrodesproducing a continuous spark in said gap when energized whereby afilament projecting from the said edge of said material moving into saidgap is severed by said spark in predetermined proximity to the said edgeof said material.

References Cited in the file of this patent

1. IN A TEXTILE MACHINE, APPARATUS FOR SEVERING THREADS PROJECTING FROMTHE EDGE OF A CLOTH COMPRISING A PAIR OF ELECTRODES SECURED INPREDETERMINED FIXED SPACED RELATION BY DIELECTRIC MEANS FORMING A SPARKGAP, A SOURCE OF ELECTRIC ENERGY OF PREDETERMINED POTENTIAL CONNECTED TOSAID ELECTRODES ADAPTED TO PRODUCE A CONTINUOUS SPARK ACROSS SAID GAP, AHOLDING MEANS ADAPTED TO RETAIN THREADS IN A SUBSTANTIALLY LINEARPOSITION FOR LATERAL ENTRANCE INTO SAID GAP, SAID HOLDING MEANSPROVIDING RELATIVE MOTION BETWEEN SAID SPARK GAP AND SAID THREADS FORENTERING THE LATTER INTO SAID GAP SPACED BETWEEN SAID ELECTRODES